I’d love to have the ability to edit Gomix files in my preferred native editor, such as VSCode. If there was a plugin to link to a given Gomix project in an external text editor that would enforce project structure and sync changes, that would be fantastic.

this would indeed be a great feature! We’ll consider it going forward – nevertheless, there are some major features coming in the next weeks that have higher precedence now.

Do you have experience with VSCode/Sublime plugins? I am a bit worried that a perfect synchronisation would be hard to achieve if they don’t support custom file listings (as the files won’t be in the local disk, but on the Gomix container) and custom “save” handlers.

I would just like to add that atom is an excellent candidate for this idea.
Everything is coded in javascript, including plugins, and there’s already a very nice open source file sync plugin that could be forked.